Seven dead as raging torrent swamps Toowoomba

Seven people are feared dead after a raging torrent of water swept through the city of Toowoomba in south-east Queensland this afternoon.

Heavy rain caused major flash flooding and landslides in the Darling Downs city, with more than 160 millimetres of rain falling in the region over the past 36 hours - most of it falling on an already saturated catchment.

Four deaths have been confirmed, and the ABC understands three others have died.

Police say a woman and child died when their car was washed away in a torrent of water in Toowoomba's CBD this afternoon.

Inspector Douglas McDonald says three people were trapped in a car, but a woman and child could not be saved.

"Only one of those persons was able to be rescued before the vehicle and the other persons were swept away," he said.

A man and a boy also died at Murphy's Creek in the Lockyer Valley when they were swept from a house.

The ABC understands two women and a girl have died at Grantham, while several others are missing in the region.

At Postman's Ridge just outside Toowoomba, a man is believed to have drowned after he was swept away in floowaters.

Rescuers are having trouble reaching the site and hold little hope of finding the man alive.

There have been nearly 30 swift water rescues in the area, and emergency services are searching waterways for several other people feared missing.

Two helicopters have joined the rescue effort, with people stranded on cars and buildings.

There is also an unconfirmed report of three children missing in nearby Gatton, in the Lockyer Valley, where flash flooding has also caused widespread damage.

Mayor Peter Taylor says the damage is enormous.

"There has been loss of life, I don't know how many at this point but I do know that at least one person's life has been lost and there's massive damage," he said.

He says the city is in shock.

"It's just a real disaster scene where I am standing at the moment in Russell Street in Toowoomba, there is actually furnishings and furniture," he said.

"It's just blown shops away, there's water literally running out of the front door of shops here as a major flash flood came through the middle of the city."

A car has been washed off a bridge on the Warrego Highway and witness Deanna Ward says vehicles have been swept down city streets.

"One car we did see come down with its lights on, it ended up crashing into one of the power poles and people were in it for quite awhile before they were rescued," she said.

A building has collapsed in the city centre and there are reports of another being washed into a creek.

"We saw a tank and a bridge go floating down the river - a water tank on top of part of a wooden bridge sort of structure all went there past the library," another resident said.

The nursing home, library and shopping centre have been evacuated, while a landslide has blocked the up section of the Toowoomba Range.

Dozens of people are stranded in buildings in the main street and there have been multiple calls for help from people stuck in or on their vehicles.

Emergency crews are struggling to cope and have had to ask a number of stranded people to stay where they are and wait for help.

Darren Burton from the Toowoomba Regional Council says he saw four cars swept down a causeway near the rail line.

"These cars were just washed down that, where they came from I'm not sure, but certainly now it's almost like a reef, water's just gushing over the top of that so you can't see any of those cars anymore," he said.

Resident Joanne Kruger says it was like being in a disaster movie.

"It was like the tide had come in dramatically, like rolling waves across the road," she said.

Premier Anna Bligh was in a meeting with her flood recovery committee when she heard about the unfolding crisis in Toowoomba.

"Just as we might be moving to a stabilised situation this afternoon in an emerging and evolving situation there has been a massive deluge in the city of Toowoomba," she said.

"The creeks through the centre of the city have overflowed, there are swift water rescues being undertaken and the city of Toowoomba is effectively split."

David Grant from the weather bureau says more rain is on the way.

"There was a brief reprieve around Toowoomba, however there has been further rainfall push across the area that may last for the next hour or so, probably return to more patchier rain before we probably see a redevelopment later on in the afternoon into the evening," he said.

Assistant Commissioner Tom Dawson from the Fire and Rescue Service says it has been a chaotic day in the city.

He says 90 calls for help were received from Toowoomba at the height of the flood, including 32 that were life-threatening.

"We also had 24 other rescues, people trapped on buildings, on roofs, trapped in buildings and things of those nature," he said.

"We're going to continue to plan to sustain and endure through this weather event, working very closely with the police, ambulance and SES.

"We're in it for the long haul, but certainly we took a big hit today."

'Absolute devastation'

A flood evacuation alert has been issued for residents living near Lockyer Creek at Gatton, east of Toowoomba.

Flash flooding has also affected the area and several people are reportedly missing.

Police say two vehicles have been swept from the road at Withcott and have not been found.

Lockyer Valley Mayor Steve Jones says there is widespread damage.

"Houses washed off their stumps and gone down the creek, huge amounts of flooding, enormous damage around Withcott," he said.

"It looks like Cyclone Tracey has been through. Communications have been very sketchy ... cars have floated off all sorts of things."

Councillor Jones says evacuations will be necessary.

"We've got absolute devastation, huge amounts of flooding, there will be a lot of people evacuated," he said.

"It's early days yet and we're yet to sort of get all that in place."

People were stranded on roofs in Grantham, near Gatton, where residents say the water rose about a metre every few seconds.

"As far as the eye can see north, south, east and west is just water," one local resident said.

"I've been here since 1960 and I have never ever seen water like it."

An evacuation centre has been set up at the state school in Withcott, near Toowoomba, for local residents and those in trouble at Murphys Creek.

Rain is bucketing down in the southern inland town of St George, adding to the flood crisis there.

And heavy rainfall has also caused flash flooding at Esk in the Brisbane Valley. Many roads in the area are closed because of landslips and the council office has been flooded.

Residents are also evacuating homes in low-lying areas of Stanthorpe on the Granite Belt.

As well as Toowoomba, emergency services in Queensland are focused on Dalby and Gympie in the state's south-east, which are both on flood alert.